Matsutake - a prized edible mushroom in Japan

By the late 1980s work at Invermay Agricultural Centre on the PÈrigord black truffle (Tuber melanosporum - Hall, Brown & Byars 1994; Hall, Buchanan, Wang & Cole 1998) was progressing and it was decided to extend the programme to include other edible mushrooms. A number of saprobic mushrooms which had sizable overseas markets were considered but all were dismissed as viable options because there was a question whether those produced in New Zealand would be able to compete on the world market with those produced by China and other developing countries. Attention was, therefore, directed to the other important edible ectomycorrhizal mushrooms of commerce particularly matsutake (Tricholoma matsutake and similar species - Wang, Hall, Evans 1997), porcino (Boletus edulis - Hall, Lyon, Wang, Sinclair 1998), the Italian white truffle (Tuber magnatum - Hall, Zambonelli, Primavera 1998) and chanterelle (Cantharellus cibarius - Danell 1994). The principal reasons for this were:

Of the major ectomycorrhizal mushrooms of commerce only porcino has made the accidental journey to the Southern Hemisphere and consequently out-of-season in the Northern Hemisphere fresh mushrooms of most of these species are unavailable.

Mushrooms of these species are best eaten fresh and their shelf life is only a few weeks in the refrigerator.

!Fresh mushrooms of these species fetch high to very high prices.

Most of these species have never been cultivated (Hall, Buchanan, Wang & Cole 1998; Hall & Wang 1998) and thus presented a significant challenge.

Consequently, when the first author was invited to join the staff at Invermay Agricultural Centre Research in 1990 it was specifically to work on the cultivation of Tricholoma matsutake and other edible ectomycorrhizal mushrooms with a view to producing these in New Zealand for off-season Northern Hemisphere markets.

Tricholoma matsutake

Matsutake (matsu = pine; take = mushroom) is the collective Japanese common name for a group of similar mushrooms formed by closely related Tricholoma spp. which has been adopted to include a number of other species in Europe, USA and Canada. Matsutake has been considered an autumn delicacy in Japan for many hundreds of years and fills a niche in the Japanese gourmet market similar to truffles in Europe ( Wang, Hall & Evans 1997). In 1940 Japan produced about 12,000 t of matsutake but over the past 60 years yields have declined dramatically (Figure 1). Now in a good year, Japan produces 1,000 t with an additional 2000 t imported from China and Korea (T. matsutake), Morocco (T. caligatum) and North America (T. magnivelare).

T. matsutake forms distinctive white to pale grey, compact fungal colonies in the soil called shiro (<[ = white, castle or place) which are formed between host trees or occasionally around them and develop de novo when a forest is about 20 years old. The surface of the shiro is just below the litter layer and in deep soils can be 25 cm from top to bottom. Production normally begins soon after the formation of the shiros when typically there are 2000 to 5000 trees per hectare, the P. densiflora host plants are about 4 to 5 m high and generally the shrub and herb layers are poorly developed. Production reaches a maximum of up to 100 kg/ha in 40 to 50-year-old forests but gradually declines over the following 30 to 40 years as the litter layer builds up and P. densiflora is replaced by other plant species such as deciduous oaks. T. matsutake fruiting bodies begin to open as soon as they break through the soil surface and considerable expertise is required to recognise the tell-tale cracks and bulges that indicate that a highly prized, phallic shaped grade 1 fruiting body is just below the soil surface.

In the USA individual collectors sell to wholesalers who set up buying stations in local towns. The matsutake are then taken overnight to the nearest airport by trucks. In remote areas they are often flown out. Prices are largely determined by supply and demand. This is also the case in China but pickers often receive a relatively low price because much of the crop is preserved rather than marketed fresh. In South Korea the market is completely controlled by the Forest Service and a cooperative, which helps stabilise the market and maximise returns to the pickers.

New Zealand research

Although T. matsutake has never been cultivated, because parts of New Zealand has summer climates resembling those in the Hokkaido, Iwate and Yamagata T. matsutake (Wang, Hall & Evans 1997) we felt justified in trying to grow this mushroom for the out-of-season Japanese markets. We first obtained or isolated cultures of T. matsutake, T. bakamatsutake, T. caligatum and T. magnivelare from Japan, China, Europe and North America. These cultures required special treatment as they were invariably very slow growing often producing as little as 1 mm per month on agar. The next step was to identify those isolates which grew the fastest on a range of agars, solid and liquid media. Subsequently mycorrhizas were established between T. matsutake and Pinus densiflora and P. radiata.

In the mycorrhizal synthesis experiments the T. matsutake isolates initially formed loose cotton wool-like aggregations of hyphae around the Pinus roots. Surprisingly, despite their very slow growth many of the cultures then became very aggressive destroying the root cortex and in severe cases killing the plant. Under some circumstances T. matsutake primordia developed on the roots.

Problems with T. matsutake killing host plants in mycorrhizal synthesis experiments have now been overcome and sufficient infected P. densiflora and P. radiata are being raised to establish field experiments. However, because we are still a little concerned that under some circumstances T. matsutake may be pathogenic to the host plant we have decided to conduct the preliminary trials either in a country where matsutake is already found or on an island away from the New Zealand mainland.

Bibliography

Danell, E. 1994. Cantharellus cibarius: mycorrhiza formation and ecology. Comprehensive summaries of Uppsala dissertations from the faculty of science and technology 35. Acta Universitatis Upsalensis, Uppsala.

Hall, I.R.; Brown, G.; Byars, J. 1994. The black truffle: its history, uses and cultivation. Edit. 2. New Zealand Institute for Crop & Food Research Limited, Christchurch, New Zealand.

Hall, I.R.; Buchanan, P.K.; Wang, Y.; Cole, A.L.J. 1998. Edible and poisonous mushrooms: an introduction. New Zealand Institute for Crop & Food Research, Christchurch.

Hall, I.R.; Lyon, A.J.E.; Wang, Y.; Sinclair, L. 1998. Ectomycorrhizal fungi with edible fruiting bodies. 2. Boletus edulis. Economic botany 52: 44-56.

Hall, I.R.; Zambonelli, A.; Primavera, F. 1998. Ectomycorrhizal fungi with edible fruiting bodies. 3. Tuber magnatum. Economic botany 52: 192-200.

Hall, I.R.; Wang, Y. 1998. Methods for cultivating edible ectomycorrhizal mushrooms. In: Mycorrhiza manual, ed. A. Varma. Springer Laboratory Manual. Springer Verlag, Heidelberg. Pp 99-114.

Molina, R.; Palmer, J.G. 1982. Isolation, maintenance, and pure culture manipulation of ectomycorrhizal fungi. In: N.C. Schenck (ed) Methods and principles of mycorrhizal research. American Phytopathological Sciety, St Paul. Pp 115-129.

Wang, Y.; Hall, I.R.; Evans, L. 1997. Ectomycorrhizal fungi with edible fruiting bodies. 1. Tricholoma matsutake and allied fungi. Economic botany 51: 311-327.

(The books by Hall, Brown & Byars and Hall, Buchanan, Wang & Cole are available from Alex Lemon, New Zealand Institute for Crop & Food Research, P.B. 4704, Christchurch, New Zealand, fax +64-3-325 2074, email LemonA@crop.cri.nz)

Back to proceedings.